Apparatus of various designs have already been proposed for the treatment of dental roots. Some of these apparatus (for example German Patent No. 691,027, DOS 1,072,772, Swiss Patent No. 611,508, US Patent No. 3,919,775) use, in order to introduce a cleaning or treatment liquid inside the tooth to be treated, a pipe, the outlet end of which is engaged as far as possible inside the radicular channel(s) of the tooth. However, these channels are so narrow that it is difficult, if not impossible, to reach properly the apex of the tooth with this liquid, thus resulting in unsatisfactory treatment.
In the Swiss Patent No. 603,145, a connection piece provided with a liquid supply pipe and a liquid discharge pipe is placed in a sealed manner on an opening formed in the part of the tooth located opposite the root. So as to ensure that the inside of the tooth is properly cleaned, it is proposed, in this patent, to convey the liquid into the tooth by subjecting it to periodic pulses combined with oscillations of substantially greater frequency. However, experience has shown that this solution does not permit complete cleaning of the inside of the tooth, nor ensures that the treatment or cleaning liquid fills the radicular channels completely a necessary condition, however, for thorough cleaning of the inside of the tooth.